DSA-1305-1 icedove -- several vulnerabilities

Several remote vulnerabilities have been discovered in the Icedove mail client,
an unbranded version of the Thunderbird client. The Common Vulnerabilities and
Exposures project identifies the following problems:

Gatan Leurent discovered a cryptographical weakness in APOP
authentication, which reduces the required efforts for an MITM attack
to intercept a password. The update enforces stricter validation, which
prevents this attack.

Fixes for the oldstable distribution (sarge) are not available. While there
will be another round of security updates for Mozilla products, Debian doesn't
have the resources to backport further security fixes to the old Mozilla
products. You're strongly encouraged to upgrade to stable as soon as possible.

For the stable distribution (etch) these problems have been fixed in version
1.5.0.12.dfsg1-0etch1.